Animated electrical discharge device



June 6, 1939. 1. H. MCCAULEY 2,161,716

'ANIMATED ELECTRICAL DISCHARGE DEVICE Filed Jan. 25, 1939 Patented `lune 6, 1939 UNITED STATES PATENT oFFicE ANIMATED ELECTRICAL DIS CHARGE DEVICE Application January 25, 1939, Serial No. 252,829

Claims.

This invention relates to luminous electrical discharge devices. In my patents, No. 2,132,427 and No. 2,133,206, I have shown such devices, each comprising a closed glass tube or envelope con- 5 taining electrodes and a rare gas and a ller of insulating material within the envelope which provides a plurality of passageways for the electrical discharge. The discharge, in passing through the envelope, follows the course of least 1o resistance and, in the part of the tube containing the filler, shifts from passageway to passageway,

causing a flickering eiect. In the structures illustrated in said patents, I have shown electrically conductive material applied externally to the tube or envelope, adjacent that part containing the ller, and this causes active shifting of the discharge throughout said portion.

In the present invention, instead of providing an envelope with a filler contained therein, I

provide a glass unit, which forms part of the envelope, this unit being of tubular form and having a series of longitudinal grooves in its inner wall. A piece of insulating material fits within the unit and closes the open sides of the grooves,

thus converting the grooves into independent passageways through which the discharge may take place. In order to accelerate the shifting of the discharge from groove to groove, I arrange electrically conductive material upon or closely 3o adjacent the unit.

In the accompanying drawing,

Fig. 1 is a longitudinal central section through a tubular glass unit of cylindrical form having a plurality of longitudinal grooves in its inner wall,

the section being taken on the line I-l of Fig. 2;

Fig. 2 is a cross-section through the same on the line 2 2 of Fig. 1;

Fig. 3 is a side View of a core of insulating material adapted for insertion in the unit shown in Figs. 1 and 2;

Fig. 4.- is a longitudinal section through the aforesaid unit with the core inserted therein;

Fig. 5 is an end view of the same;

Fig. 6 is a side View of an electrical discharge device having one of the grooved units incorporated therein;

Fig. 7 is a similar view of a discharge tube having several of said units incorporated therein;

Fig. 8 is a plan View of a discharge device having a flattened glass unit incorporated therein;

Fig. 9 is a section on the line 9-9 of Fig. 8, and,

Fig. 10 is a section on the line lll-lll of Fig. 8.

Referring first to Figs. 1-5, inclusive, of the drawing, a represents a piece of glass tubing molded with a circular series of longitudinal grooves I in its inner wall, the grooves being all alike in length and cross-section. The ridges la between the grooves project inwardly to the same radial distance from the axis of the tube. A cylindrical core of insulating material 2 (Fig. 3), 5 when inserted in the tube, fits against these ridges and closes the open side of all of the grooves, as shown in Figs. 4 and 5, thereby converting the grooves into separatefand independent passageways through which the electrical discharge may l1() pass when the unit is made part of a luminous electrical discharge device. The core 2 may be made of any suitable insulating material which will not be affected by the electrical discharge. Like the tubular part a, the core may be made of 15 glass, either clear or colored, but preferably the core is made of white ceramic material which is light in weight and reflects the light caused by the discharge. If desired, the core may consist of a tube of glass or other insulating material 20 closed by a plug or otherwise so that the electrical discharge cannot pass through the core and will be forced to take the course through the grooves.

The ends of the unit a are'suitably formed for *.25 connection to other units, or for connection in any part of a luminous electrical discharge tube.

As shown in Figs. 1, 4 and 5, sockets 3 are formed in the ends ofthe units and the ends of the socket walls are joined to sections of tubing 4, closed at 30 their outer ends and containing electrodes 5. The sections 4 are sealed gas-tight to the unit G. and the sections and unit together form a closed glass envelope. Thisis exhausted and de-gasilied and then filled with a rare gas, such as neon, 35 argon or helium, or mixtures of gases, or vapors, in the usual way, and when the electrodes are connected to the high tension side of a suitable transformer, the discharge. will take the course of least resistance through the gas. The gas in 40 the parts 4 will be luminous, with a steady glow, while in passing through the unita, the discharge will shift at intervals from groove to groove, or,

depending upon the size of the grooves and the resistance of the columns of gas therein, it may 45 not shift at all. 'Ihat is, if the grooves are made relatively large in cross-section, with consequent low resistance of the gas columns in the grooves, which is desirable, the shifting of the discharge from groove to ygroove will be less active than 50 if the passageways are made smaller in diameter, with consequent gas columns of higher resistance.

In order to insure active shifting of the discharge from groove to groove, I apply electrically conductive material to the outer surface of the 55 between tubular parts 8 containing electrodes 9,-

the various parts, when sealed gas-tight, forming a closed glass envelope. When this is lled with a rare gas in the usual way and the current is Y applied to the electrodes, shifting of the ycourse of the discharge through the grooves in the several units will takeplace, Yand this shifting will be very active'because of the applicationto the units of electrically conductive 'material Thuacbands of conductive material IIA areY shown applied to opposite z ends -of the units a and -a,3,

and these are connected by a conductor I I,.Which is preferably, though notV necessarily, ,Wrapped around the units. Y Y

In Figs.Y 8, 9 and 10, I have shown an internally grooved glass unit b, in the form of a flattened tube, to the ends of which are sealed flattened tube sections I2, closed at their outer'ends and containing electrodes.V I3.' Electrically conduc-Y ti-ve'bandsVV I4, appliedl to the ends ofA the unit, are

' connected togetherY by conductor I5.`rv As shown in theV sectional View, Fig'. `9, grooves I6Y are formed on the inner side of the Wall I1 of the unit, and a flat strip of insulating material I8 is interposed between the ridges II1 which form the grooves and the opposite'side Wall I9, theV Vstrip YI8 thus closingtheiopen sides of Vall of the grooves, thereby converting the grooves into separate and independent passageways. vThe .discharge device thus vformed and lled'with a Yrare gas, operates YinY the samefway as does the Y cylindrical formof discharge device previouslyV described..-V When the' currentis applied-to Ythe electrodes, very active shifting vof the course of the current from groove to groove-takesY place,`

giving theappearance of rapidly-.shifting bands of `light when observed through they wall H, or through both Walls. I'I and I9 if the insulating strip I8 is made of glass. v

If 'the core is omitted from one of the units,

l flickering willV not take place in that unit because the current will follow the course of low resistance through the core space. Thus, in a discharge device built up as in Fig. '7 with a series of the units, if the core is omitted from the central unit a2, for instance, the gas in that unit will be luminous, with a steady glow, while in the other units a and a3 containing the insulating cores, active shifting of the discharge from groove to groove will take place'.

What I claim is:

1. An animated electrical discharge device lcomprising a closed glass envelope containing a rare gas andspaced electrodes, said envelope comprising a tubular part having a plurality of grooves in its inner side extending longitudinally of the envelope, anda core of insulating material fitting within said part and closing the open sides of said grooves. Y Y

2. Ann n animated electrical discharge device comprising a closed glass envelope containing a rare-gas and-spaced electrodes, said envelope comprisinga tubular partfhavingy a plurality of grooves in its Vinnervside extending longitudinally of .the envelope, and a ycoreof insulating material vtting within saidY part and closing the openVV sides of saidgrooves, and electricallycon` ductivejmaterial associated with said part for" influencing the course of the discharge through said grooves. Y '3. An animated grooves in Vvits inner side extending longitudinally ofthe envelope, Yand a core of insulating material f tting within-said part and closing the open sides of said grooves, and electrically conductive maelec'trical Ydischarge devicev comprising a closedglassenvelope containing a Irare gasv and spaced electrodes, --said envelope comprising a*Y tubular part: having a plurality of w terial applied: tothe outer surface of said part for inuencing the courseofvthe dischargethrough said grooves.y v

4. A unit adapted tolform Vpart of a luminousV electric discharge comprising a glass tube `having longitudinal grooves in its inner wall, and'a core 4of insulatingmaterial adapted Vto ilt within ,Y

Vvvthe tube and close theopensides of Ysaid grooves. VY.315,

V5.. A unit adapted'to form-.part of a luminous,` i

electric discharge devicecomprising a relatively `flat glass tube vhaving ,longitudinal grooves Ain one of itsrinner walls, anda core rof insulating material adapted to t within the tube andclose the open sides ofsaidfgrooves. Y. 

